After meeting inclusion criteria, one hundred-forty men and women, aged 62 to 80 years old, will be enrolled and randomly assigned to one of four groups: 1) omega-3 fatty acid and blueberry powder supplement, 2) omega-3 fatty acid and placebo powder, 3) placebo oil and blueberry powder supplement, or 4) placebo oil and placebo powder. They will participate in a 24-week intervention with major assessments including neuropsychological and functional evaluation at pre-treatment baseline and during the final week of the intervention. In addition, an interim evaluation of neurocognitive function will be conducted at 12 weeks. Subjects will be asked to maintain diet diaries for three periods during the study. Mood will be assessed as a potential covariate of the neurobehavioral outcome measures and data on red blood cell fatty acid content, metabolic parameters, inflammation, and anthropometric factors will be gathered to assess compliance and explore individual differences in response to the intervention and to evaluate potential mechanisms of action.